if you are worried about violating copyright issues with music. You need to head to:
http://www.ascap.com/weblicense/ which is a page that will tell you about getting ASCAP licensing...
not ALL artists are represented by ASCAP you may need to head to
http://www.bmi.com/ and register there as well. Those sites should give you more than enough information about staying within legal bounds when it comes to music.
Good Luck, -g